Field of the Invention
The present invention relates to a packing configuration of a cable such as an optical fiber cable.
Description of Related Art
Heretofore, a variety of optical fiber cables have been manufactured and used. For example, in each of the optical fiber cables, a so-called optical fiber core wire having a coating composed of ultraviolet curing resin, thermosetting resin or the like on an outer circumference of a glass optical fiber is prepared, and this optical fiber core wire, a pair of tension members, and further, a support wire are collectively coated while being positioned at a predetermined position, whereby a sheath is formed.
Incidentally, as a packing configuration of these optical fiber cables, there is one in which the cable is housed in a housing container in a state of being wound in a figure-of-eight shape (for example, refer to Japanese Patent Application Laid-Open Publication No. 2001-63784). In this technique, while winding the cable around a barrel-like mandrel so as to draw the figure-of-eight shape, a rotation speed of the mandrel and a pitch for winding the cable around the same are controlled, whereby a bundle is formed while forming a hole in one radial spot of the bundle.
A winding terminal end of the cable is fixed to a box-like housing container such as a corrugated cardboard box that houses this bundle. In the box-like housing container, a hole is provided at a position corresponding to the above-described hole. A cylindrical guide member is inserted into the holes of the box-like housing container and the bundle, and a winding start end of the cable is inserted through the guide member. The cable is pulled out through the guide member to the outside of the box-like housing container, whereby the cable is paid out from an inner portion of the bundle in a state of sequentially collapsing.
It is known that, when this technique is used, a twist does not occur at the time of paying out the cable since the cable is wound in the figure-of-eight shape, and moreover, even if the cable is stopped being paid out, a situation does not occur where the mandrel freely rotates like a reel by inertia to break the winding of the cable, and the cable can be paid out favorably. Therefore, this technique is generally used for a cable having some rigidity, such as a LAN cable, an optical drop cable and an optical indoor cable.
Incidentally, in recent years, an indoor cable has been developed and examined, in which a diameter and friction of an outer sheath are decreased, as a result of making much of ease in insertion and feeding thereof through a conduit, and handling thereof. When the indoor cable, in which the friction of the outer sheath is decreased or bending rigidity is decreased by reducing the diameter, is wound into a bundle shape by the above mentioned technique, then the cable on the outside of the bundle becomes prone to be broken. Therefore, in order to house the bundle in the box-like housing container so that the bundle cannot be broken, an operation by two persons is required, and such an operation is troublesome.
Moreover, since the cable only has low rigidity, when the cable is paid out from the box-like housing container, and a length of the cable remaining therein is reduced, a circular shape of the whole bundle cannot be held, and the whole bundle collapses into an ellipsoidal shape. Furthermore, since adjacent portions of the bundled cable are prone to slip on each other, there has been a problem that not only a portion thereof which is about to be paid out at the present time but also a portion thereof up to a few rounds ahead are broken in the inside of the bundle, a phenomenon occurs that the cable is paid out while entangling such a broken portion, and a bend and a knot are generated in the cable.